Dastur,. — Cytology of Tilletia Tritici , ( Bjerk. ) Wint. 401 
be a less number of nuclei in a promycelium which already bears full-sized 
sporidia (PL XX, Fig. i), or which shows evident signs of sporidial formation 
(PL XX, Figs. 6 and 7). The forking or bifurcation of the promycelial tip 
described by Paravicini has been observed, but in no case has it been found 
to be associated with nuclear divisions (PL XX, Figs, i, 6, 7, and 9). Para- 
vicini finds the sporidia nucleated, even when they are very young (cf. his 
PL V, Fig. 5). But Rawitscher 1 finds eight nuclei in the promycelium 
after it has grown to some length ; and his figure distinctly shows the 
young sporidia to be without nuclei, though there are four pairs in the 
promycelium. Dangeard 2 explicitly states : ‘ Les sporidies dans le Tilletia 
sont aciculaires ; au debut, leur protoplasme est tres dense, homogene ; a ce 
stade, il n’y a pas encore de noyau ; plus tard, il devient vacuolaire . . . ; 
c’est le moment oil les noyaux se distribuent dans les sporidies/ The 
present observations on this point are in complete accord with those of 
Dangeard. As long as the sporidia are not vacuolated the nuclei remain 
in the promycelium (PL XX, Figs. 8 and 9). 
Paravicini 3 finds the promycelium to be one-celled, or at the most 
two-celled, and in the latter case both these cells are nucleated. This 
observation is again at variance with those of Dangeard, 4 Rawitscher, 5 and 
the writer. The promycelium has been observed to be only one-celled. 
At times the protoplasm collects in the upper part of the promycelium, and 
then the empty lower part is cut off by one or more septa ; this generally 
happens in the case of a long promycelium (PL XX, Fig. 6). 
Dangeard limits the number of nuclei to eight, but as observed by 
Rawitscher and Paravicini there are, at times, more than eight nutlei in the 
promycelium (Pl. XX, Figs. 9, n, and 12). Dangeard states that if the 
promycelium branches the eight nuclei pass into the new branch ; but this 
has not been found to be invariably the case (Pl. XX, Fig. 12). 
The division of the nuclei in the promycelium does not necessarily 
take place simultaneously (PL XX, Figs. 3, 5, 7, and 11). As suspected by 
Dangeard, the nuclear division appears to be mitotic (PL XX, Fig. 3). 
The primary sporidia are, as a rule, borne apically, but on rare 
occasions they are developed on a lateral branch (PL XX, Fig. 10). They 
are usually carried on short forked branches of the promycelium (PL XX, 
Figs. 1 and 9). As already pointed out, Paravicini explicitly states that 
on the tip of the promycelium eight protuberances are developed, each of 
which bears an ‘ endconidium ’ or sporidium ; but in his Fig. 6 of Plate V 
the sporidia are shown to be borne directly on the flat promycelial end. 
The number of branches has not been observed to correspond to the number 
of sporidia. 
1 Rawitscher, F. : loc. cit., p. 313. 
3 Paravicini, E. : loc. cit., p. 76. 
5 Rawitscher, F. : loc. cit., p. 312. 
2 Dangeard, P. A. : loc. cit., p. 266. 
4 Dangeard, P. A. : loc. cit., p. 265. 
